The purpose of this study is to determine whether the bioavailability of the three HIV protease inhibitors is affected by giving them together in contrast to separating the doses by several hours. The hypothesis being tested is that since at least two of these compounds are inhibitors of P-glycoprotein, co-administration of two protease inhibitors may increase the bioavailability of both by preventing their transport out of intestinal cells by P-glycoprotein. The design is a balanced Latin square, in an effort to minimize subjects and assays. Plasma samples are obtained after simultaneous and staggered dosing, and analyzed for drug concentration by HPLC. Standard non-compartmental pharmacokinetic analysis will be used to determine the effect, if any of the different times of administration. Enrollment in the protocol is now complete, samples have been collected, and laboratory assays and data analyses are ongoing. There are no preliminary results available at the present time.